fix for bug 821252. Smarter default scheduler

compute_scheduler_driver = DistributedScheduler

Change-Id: I8123a120afd80c2b088a387eaab8f5a99a877fe0

nova/scheduler/filters/ram_filter.py

@@ -22,7 +22,7 @@ from nova.scheduler import filters
 LOG = logging.getLogger(__name__)
 
 ram_allocation_ratio_opt = cfg.FloatOpt("ram_allocation_ratio",
-        default=1.0,
+        default=1.5,
         help="virtual ram to physical ram allocation ratio")
 
 FLAGS = flags.FLAGS

nova/scheduler/multi.py

@@ -29,7 +29,8 @@ from nova.scheduler import driver
 
 multi_scheduler_opts = [
     cfg.StrOpt('compute_scheduler_driver',
-               default='nova.scheduler.chance.ChanceScheduler',
+               default='nova.scheduler.'
+                    'distributed_scheduler.DistributedScheduler',
                help='Driver to use for scheduling compute calls'),
     cfg.StrOpt('volume_scheduler_driver',
                default='nova.scheduler.chance.ChanceScheduler',

nova/tests/api/ec2/test_cloud.py

@@ -94,6 +94,8 @@ class CloudTestCase(test.TestCase):
         self.stubs.Set(utils, 'usage_from_instance', dumb)
         # set up our cloud
         self.cloud = cloud.CloudController()
+        self.flags(compute_scheduler_driver='nova.scheduler.'
+                'chance.ChanceScheduler')
 
         # set up services
         self.compute = self.start_service('compute')

nova/tests/fake_flags.py

@@ -42,4 +42,5 @@ FLAGS.set_default('use_ipv6', True)
 FLAGS.set_default('flat_network_bridge', 'br100')
 FLAGS.set_default('sqlite_synchronous', False)
 flags.DECLARE('policy_file', 'nova.policy')
+flags.DECLARE('compute_scheduler_driver', 'nova.scheduler.multi')
 FLAGS.set_default('policy_file', 'nova/tests/policy.json')

nova/tests/integrated/integrated_helpers.py

@@ -69,6 +69,8 @@ class _IntegratedTestBase(test.TestCase):
             image_id = str(image_href).split('/')[-1]
             return (nova.image.fake.FakeImageService(), image_id)
         self.stubs.Set(nova.image, 'get_image_service', fake_get_image_service)
+        self.flags(compute_scheduler_driver='nova.scheduler.'
+                    'chance.ChanceScheduler')
 
         # set up services
         self.compute = self.start_service('compute')

nova/tests/scheduler/test_host_filters.py

@@ -177,6 +177,7 @@ class HostFiltersTestCase(test.TestCase):
     def test_ram_filter_fails_on_memory(self):
         self._stub_service_is_up(True)
         filt_cls = self.class_map['RamFilter']()
+        self.flags(ram_allocation_ratio=1.0)
         filter_properties = {'instance_type': {'memory_mb': 1024}}
         capabilities = {'enabled': True}
         service = {'disabled': False}